DFIT interpretation has been a theme of the work that we’ve done within ResFrac. Our collaborative 2018 Industry Study, which culminated in one of the ‘Best of URTeC’ papers in
Parent-child interactions have been a continual challenge for the unconventional oil and gas industry in recent years. At HFTC 2022, Devon and ResFrac co-authored a study on modeling parent-child interactions in the STACK in Oklahoma (SPE 209152). The parent well, two generations of children wells, and a remediation treatment in the parent well are modeled in a single, continuous ResFrac model. The continuous nature of the ResFrac modeling allowed for fluid exchanges between parent and children wells to be captured, while also requiring a holistic explanation for performance degradation in parent well post-hit. The model quantitatively described all historical observations (including damage to parent and subsequent recovery after remediation treatments) and is now suited for optimization of child well design and parent remediation programs.
The main parameters of interest derived from a diagnostic fracture injection test (DFIT) are minimum in-situ stress, reservoir pressure, and permeability. The latter two can only be obtained uniquely from the transient reservoir responses, often requiring days to weeks of test time. The DFIT flowback analysis (DFIT-FBA) method, a sequence of pump-in/flowback (PIFB), is a fast alternative to the pump-in/falloff (conventional) DFIT for estimating minimum in-situ stress and reservoir pressure.
The problem of a plane strain hydraulic fracture propagating in a layered formation is considered. Fracture toughness, in-situ stress, and leak-off coefficient are assumed to vary by layer, while the elastic properties are kept constant throughout the domain for simplicity. The purpose of this study is to develop a numerical algorithm based on a fixed mesh approach, which is capable to solve the above problem accurately using elements which can even be larger than the layer size.
For Office Hours this month, we had a presentation from ResFrac Senior Reservoir and Completions Engineer, Rohan Irvin, on optimizing well spacing and completion design using simulation models calibrated to the Hydraulic Fracture Test Site 2 (HFTS-2) dataset.
This Office Hours presentation from Mark McClure on refracturing, automated history matching, and automated economic optimization covers a ResFrac case study using a public ‘refrac’ dataset on which we perform an automated history match to the original and ‘post-refrac’ dataset. Then, we perform an automated economic optimization on job size for the refrac design.
For Office Hours this month, we had a presentation from Mark McClure entitled, “Direct Validation of DFIT Interpretations from In-Situ Strain Measurements,” reviewing a presentation he gave on April 11, 2022, at Saga Wisdom’s Sökkvabekkr conference in Austin, TX.